Memory cells configurable as CAM or RAM in programmable logic devices
First Claim
Patent Images
1. An integrated circuit, comprising:
- a dual mode function block programmably suitable for operating as a first type function block in a first mode and as a second type function block in a second mode, wherein each dual mode function block includesa first type function cell arranged to perform a first type function,a second type function cell arranged to perform a second type function, andan isolation circuit for electrically decoupling the first type function cell from the second type function cell wherein the dual mode function block operates exclusively as the first type function block when the isolation circuit is not activated and wherein the dual mode function block operates exclusively as the second type function block when the isolation circuit is activated.
0 Assignments
0 Petitions
Accused Products
Abstract
A programmable logic device having content addressable memory is disclosed. In a preferred embodiment, the programmable logic device includes reconfigurable dual mode memory suitable for operating as a content addressable memory in a first mode and a random access memory in a second mode is disclosed. Mode control switch circuitry may be provided to selectively enable a user to configure the dual mode memory as either content addressable memory or random access memory.
71 Citations
18 Claims
-
1. An integrated circuit, comprising:
a dual mode function block programmably suitable for operating as a first type function block in a first mode and as a second type function block in a second mode, wherein each dual mode function block includes a first type function cell arranged to perform a first type function, a second type function cell arranged to perform a second type function, and an isolation circuit for electrically decoupling the first type function cell from the second type function cell wherein the dual mode function block operates exclusively as the first type function block when the isolation circuit is not activated and wherein the dual mode function block operates exclusively as the second type function block when the isolation circuit is activated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
12. A method for causing an integrated circuit to operate as a content addressable memory device in a first mode and as a static random access memory device in a second mode, wherein the integrated circuit includes a dual mode memory block, the dual mode memory block including an array of dual mode memory cells, each dual mode memory cell being suitable for operating as a content addressable memory in a first mode and as a static random access memory in a second mode, wherein each dual mode memory cell includes a data storage circuit for storing data, a comparison circuit for comparing data stored in the data storage circuit with requested data, and a match line for indicating whether the stored data and the requested data match, wherein each dual mode memory cell is coupled to an isolation circuit for electrically decoupling the data storage circuit from the comparison circuit and match line, the isolation circuit, in turn, being coupled to a mode control switch circuit suitable for selectively enabling the dual mode memory cells to operate in either the first or second modes, comprising:
-
providing a second mode select signal to the isolation circuit by the mode control switch circuit; and activating the isolation circuit by second mode select signal such that the isolation circuit electrically decouples the data storage circuit from the comparison circuit in such a way that the dual mode memory cell operates exclusively as a static random access memory device. - View Dependent Claims (13, 14, 15, 16, 17, 18)
-
Specification